prelude, prélude, präludium [G], praeludium, preludio—a movement preceding another almost by way of introduction: to let listeners and players acclimate, often to prepare for greater demands ahead

sonata, sonate, suonato—a complicated term. Originally, "sounded" rather than "sung" (sonar vs. cantar), e.g. instrumental music. According to historical period, sonata began to imply a formal plan of movements as well as the structure within a single movement, e.g. sonata form. In general usage as a work title, it designates a multi-movement piece for solo or duo instruments with one of the instruments enjoying a feature role.